Photodecarbonylation of Diphenylcyclopropenone – a Direct Pathway to Electronically Excited Diphenylacetylene?

Abstract

Abstract A comparison of combined IR and UV/Vis pump-probe measurements of diphenylcyclopropenone (DPCP) and diphenylacetylene (DPA) provides clear evidence that the photodecarbonylation of DPCP following excitation to its S 2-state proceeds non-adiabatically to the electronic ground state of DPA. It is shown that transient absorption of electronically excited DPA is caused exclusively by photoexcitation of ground state DPA generated by preceding DPCP photodecarbonylation.